Grinding tools used for grinding flat glass and other materials



Jam 1958 R. TOUVAY GRINDING TOOLS USED FOR GRINDING FLAT GLASS AND OTHER MATERIALS Filed May 2, 195a dbL\ ' J/ QM 2122 6313 GRINDING TOOLS USED FOR GRINDING FLAT GLASS AND OTHER MATERIALS Robert Touvay, Paris, France, assignor to Societe Ano' nyme des Manufactures des Glaces et Produits Chimiques de St. Gohain, Chauny & Cirey, Paris, France, a French company Application May 2, 1956, Serial No. 582,270 Claims priority, application France May 3, 1955 Claims. (Cl. 51-209) The present invention relates to rotary tools, called runners, used for the grinding of sheets or plates of glass or other materials.

It is known that the grinding surface of these rotary tools is in the form of an annulus which is intersected by distributing channels which open into the central aperture of the tool which is surrounded by the annular grinding surface, and extend to near the peripheral wall of the tool by which the outer ends of the channels are closed. The liquid abrasive suspension is ture under a certain head and spreads into the distributing channels under the influence of this head and the centrifugal force generated as the tool rotates. It is evacuated towards the exterior through the ends of the channels as these, in the course of the rotation, overlap the side edges of the ribbons of glass being ground by the tool.

It has been observed that this evacuation of abrasive, which is pulsatory in nature, might be insufficient so that a suitable circulation of new abrasive might not always be assured for the working surfaces.

The main object of the invention is to remedy this disadvantage. It consists in creating at the outer ends of the feed channels an opening determined as a function of the supply of abrasive to be assured and of the pressure to be maintained in the channel.

The invention thus enables the evacuation of abrasive from the channels to be assured during the whole cycle of the tool, and not only at the moment when the end of the channel overlaps the ribbon of glass, whilst maintaining in the channel the liquid pressure considered suitable.

These evacuation openings will advantageously be of easily adjustable section so as to enable the best feed to be obtained in each case.

The evacuation opening may be in the form of an aperture made in the end and at the bottom of the channel.

This opening could be equipped with any means enabling its section to be adjusted at will: needle valve, rubber connector adjustable by tightening or the like.

According to another method of realisation of the invention, communication of the peripheral end of the channels with the outside is obtained by continually grinding, in the course of grinding the glass, the edge of the frictional surface of the runner by means of a grindstone, or equivalent, over a width sufficient to reach the said channels and over a depth suitable for constantly obtaining the desired evacuation section.

In order that the invention may be more clearly understood reference will now be made to accompanying diagrammatic drawings which show by way of example some preferred embodiments of the invention in which:

Figure l is a fragmentary vertical section at the periphery of a grinding runner in accordance with the invention, showing an aperture formed at the bottom of an abrasive distributing channel.

Figure 2 is a vertical section similar to Fig. l of modified construction showing an aperture formed at the fed to the central aper- United States Patent 0 bottom of a feed channel in the surface of the grinder away from the grinding surface.

Figure 3 is a view in elevation of another method of carrying the invention into effect.

Figure 4 is a plan view of the construction shown in Figure 3, and

Figure 5 is a sectional elevation taken on the line Y-Y' of Figure 4.

In the drawings like references designate the same or similar parts.

Referring to the drawings the sheet of glass 1 is carried by a table 2 which moves continuously perpendicularly to the plane of Figure 3. The grinding runner 3 shown lies in contact with the upper surface 4 of the sheet of glass, and rotates round the vertical axis X-X. In known manner, it has a central aperture 5 to which abrasive, usually sand, is fed in suspension in water and an annular grinding surface 6 surrounding the central aperture. Abrasive distributing channels such as 7-8 subdivide the grinding surface into elongated grinding nogs 9. The channels 78 open at 10 into the central aperture of the runner and are closed, as indicated at 11 near to the periphery 12 of the runner. The runner is of a diameter to overlap each edge of the sheet of glass 1 as indicated at 13-13 As clearly indicated in Figure 1 an aperture 14 is formed in the peripheral wall 12 of the runner, at the base of the distributing channel 8 and near to its closed end. The cross sectional area of the aperture 14 is smaller than the cross section of channel 8 so that a certain predetermined pressure on the abrasive liquid in the channel is maintained and at the same time an evacuation of this liquid outside of the runner is assured in a constant manner during the whole of the rotation of the runner.

The exit area assured by aperture 14 remains constant so long as the wear on the runner has not brought the working plane to reach the level of this aperture. From this moment, the effective evacuation area diminishes.

This latter circumstance cannot occur in the construction shown in Figure 2 where the evacuation aperture 14 opens outside the runner, not from the peripheral wall 12 of the runner, but on its horizontal top surface 15, which is not in contact with the glass 1.

In order to create freedom, in accordance with another method of carrying out the invention, at the end of channels 7-8, a means, forming a characteristic of the invention, consists, as shown in Figures 3, 4, 5, in arranging in contact with the edge of the runner one or more grindstones 15 set in rotation by motors 17. These grindstones wear away the periphery of the grinding surface to a depth a over a width b sufficient to reach the end of channels 7-8, thus creating above the surface of the glass an outlet from these channels towards the outside under the runner. The section offered for the evacuation of the abrasive through this outlet is proportionate to the height a, which enables this evacuation section to be given the desired value.

As the runner wears away, the grindstones 16 progressively wear away, the marginal edge of the runners from the depth a so that the passage thus made at the peripheral end of the feed channels preserves the same section while the runner remains in service, thus the peripheral edge of the grinding surface is selectively rabbeted and the selected peripheral form of the grinding surface is maintained during the useful life of the runner.

Of course, means will be provided allowing of regulating, in the course of working, the position of grindstones 15 so as to compensate at one and the same time for the wear of the runner and of the grindstones themselves, so as to keep depth a at a constant value. Such a means, visible on Figure 3, consists, for example, in a screw 18 supporting motor 17, the vertical displacement of which can be effected by means of a hand-wheel 19 fixed as regards height.

Without departing from the scope of the invention, the grindstones may be replaced by an abrasive stone carried .by an arm assuring a constant adjustable pressure, or by any other suitable tool.

I claim:

1. A rotary grinding runner of the kind comprising a central aperture into which is fed abrasive in suspension in water and an annular grinding surface surrounding the central aperture, the grinding surface being intersected by abrasive distributing channels the inner ends of which open into the said central aperture and the outer ends (the closed ends) terminate near the peripheral wall of the runner, characterised in that the peripheral wall of the runner is formed to provide a regulated outlet, for the abrasive fluid from the closed end of each distributing channel to the outside of the runner, the cross sectional area of the outlet being such as to assure the intended pressure on the abrasive fluid in the channels being maintained during rotation of the runner and a suitable inflow of the abrasive fluid.

2. A rotary grinding runner according to claim 1, in which the regulated outlet from each distributing channel is constituted by an apertured peripheral wall to the runner, there being as many apertures as there are distributing channels each aperture being located near the base of the channel at the closed end thereof.

3. A rotary grinding runner according to claim 1, in which the regulated outlet from each distributing channel is constituted by an apertured surface to the runner, said apertured surface being the surface opposite to the grinding surface of the runner, said apertured surface having as many apertures as there are distributing grooves, each aperture being located at the base of the channel at the closed end thereof.

4. A rotary grinding runner according to claim 1 wherein the grinding surface of the runner is rabbeted to form the outlets from the channels at their closed end, the extent of the rabbetting regulating the outflow from the channels.

5. A method of regulating the outflow of abrasive fluid from grinder runners comprising a central aperture into which is fed abrasive in suspension in Water and an annular grinding surface surrounding the central aperture the grinding surface being intersected by abrasive distributing channels the inner ends of which open into the said central aperture and the outer ends (the closed ends) terminate near the peripheral wall of the runner characterised by progresssively grinding the peripheral wall of the grinder as Wear takes place on the runner surface to maintain constant a cross sectional area of a rabbetting effected on the peripheral wall and thereby maintain constant the rate of outflow of abrasive fluid from the closed ends of the distributing channels.

References Cited in the file of this patent UNITED STATES PATENTS 670,593 Murnane Mar. 26, 1901 2,019,171 Cassity Oct. 29, 1935 FOREIGN PATENTS 507,816 Belgium June 13, 1952 526,919 Great Britain Sept. 27, 1940 

